Workpiece processing, such as solar cell or semiconductor wafer processing, requires a plurality of steps to achieve the finished product. In some embodiments, the workpiece must be moved from a station which performs one of these steps to another station which performs a different step. In some cases, the workpiece is placed in a carrier, which holds and protects the workpiece during these transitions.
However, these carriers are often constructed such that they hold or envelop the edges of the workpieces, thereby covering at least a portion of the workpiece. As a consequence, in some cases, the workpiece typically must be removed from the carrier to be processed, adding time and complexity to the process. In those cases where processing is performed on the workpiece while in the carrier, additional steps are often required to insure that the edges, which were blocked or obscured by the carrier, receive the same treatments as the remainder of the workpiece. Again, these extra steps add time and complexity to the process. Furthermore, in some cases, the edges of the workpiece that are covered during the processing may not be treated in another process step, reducing the efficiency or performance of the workpiece.
Additionally, during workpiece processing, it is often necessary to place a mask in front or on top of the workpiece to limit the exposure of the workpiece to energy, typically in the form of ions or light. This mask must be precisely aligned to the workpiece to insure that the workpiece is properly processed. Unfortunately, this critical alignment may be compromised by various forms of errors, such as thermal expansion of the mask or other materials that are not thermally matched with regard to the coefficient of thermal expansion (CTE) during processing, misalignment of the mask to the workpiece, general tolerance stack ups, workpiece irregularities, and other issues.
Therefore, it would be beneficial if there were a carrier that could be used to hold a workpiece, such that the carrier did not block or obscure the edges of the workpiece, thereby allowing complete processing of the workpiece while in the carrier. Furthermore, it would be beneficial if this carrier facilitated the alignment of a mask to the workpiece. Still further, it would be advantageous if this carrier were able to hold a plurality of workpieces and a plurality of masks, each associated with one of the workpieces.